Optimization of the method of detection of metabolites produced by the Alternaria genus: Alternariol, alternariol monomethyl ether, altenuene, altertoxin I and tentoxin

A simple method has been developed in this work for the detection of alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), altertoxin I (ATX-I), tenuazonic acid (TA), and tentoxin by means of thin-layer chromatography from cultures of several strains of Alternaria. Strains were incubated in 2% malt extract broth for 7 d at 25°C. For extraction of metabolites, chloroform was used. The solvent system benzene/methanol/acetic acid (92:6:2) was chosen. TLC plates were observed under ultraviolet light (254/366 nm). Results show that A. alternata IMI 354942 produced AOH, AME, ALT, ATX-I, tentoxin, and TA; A. alternata IMI 354943, AOH, AME, and TA; A. triticina IMI 289962 tentoxin; and A. triticina IMI 289680 AME, ATX-I, and TA.